1. Field of the Invention
The invention disclosed and taught herein relates generally to blood extraction devices and methods. More specifically, the invention relates to vacuum assisted lancing devices and methods useful for extracting a quantity of blood for sampling or testing.
2. Description of the Related Art
There are many medical reasons where a small quantity of blood needs to be drawn from a human. Determining blood glucose levels for diagnosis and treatment of diabetes is one of the most common applications where access to blood is required. Diabetes has become a significant health risk in the United States and other parts of the world. The rise in diabetes has caused alarm in the medical community. Major companies, research institutions, and the consuming public are collectively spending significant resources for the prevention, testing, and treatment of diabetes. A person with diabetes is generally required to test their blood several times a day for glucose levels and take corrective action if needed. Failure to test and take corrective action when necessary can result in injury, both long and short term degradation of the human body's functions, and in some cases death.
Currently, the market provides an assortment of devices that lance the skin producing a wound or other opening from which blood can be extracted. However, most require testing on an area of a user's skin that has a high concentration of blood vessels near the surface of the skin so that the lance can produce an acceptable quantity of blood. The most common area for testing is the finger tips, although the toes have also been used. However, these heavily vasculated areas of the human body are typically highly sensitive, having a rich supply of nerve endings. As a result, blood rich areas, such as the finger tips, often are more pain sensitive than other less vasculated areas. Thus, the very areas that are ideally suited for extracting blood for testing are the most sensitive to pain.
For those individuals who are required to test themselves, the frequent testing can have negative effects on their emotional health, physical health, and even personalities. At the least, in an effort to avoid pain, they are motivated to not test as often as required by their physician. A loss of frequency and continuity in the testing can lead to physical and emotional complications, or a significant loss of accuracy in determining proper dietary corrections and medicine regiments. Health care practitioners may also be required to lance a patient's skin to extract blood for testing, which is typically done in the fingers. In some situations, however, the fingers and toes may not be available for testing, such as when these areas of the patient's body are bandaged or injured, and an alternative testing site on the patient's body may be required.
Some blood extraction devices simply lance the skin and the patient manually squeezes the area to produce the required quantity of blood. Other blood extraction devices seek to use a vacuum to enhance the blood recovery from the lancing. However, in surveying the market of such devices, the inventor has realized that the vacuum assisted devices are either not portable with mechanized vacuum pumps, which can significantly diminish their value for mobile patients, or require unwanted maintenance, such as replacement of batteries, which are not always available. Further, many of such devices fail to adequately produce a desirable quantity of blood from portions of the skin other than the fingers and toes. Newer devices house multiple lances in the same holder, and with each use a new lance is automatically selected and used such that the patient never uses the same lance twice. Many, if not all, of these devices, including the ones that apply a vacuum, have been unsuccessful in reliably extracting sufficient quantities of blood from areas of the skin less painful than the fingers and toes. Reduction or elimination of pain has been shown to appreciably encourage the patient to follow the testing procedure prescribed by an attending physician.
While each of these devices may have certain limited applications, there remains a need to provide a simplified and improved vacuum assisted lancing device that can be routinely used at various places on the skin and still extract a sufficient quantity of blood for the required test.